Electrical information storage circuits



April 15, 195s E. P. G. WRIGHT ETAL ELECTRICAL INFORMATION STORAGECIRCUITS Filed Sept. 24.. 195] 4 Sheets- Sheet 1 April 15, 1958 E. P. G.WRIGHT ET AL 2,831,150

ELECTRICAL INFORMATION STORAGE CIRCUITS Filed Sept. 24, 195] 4Sheets-Sheet 2 MCTI McT4 MR4 p il MRss MRS V T T T MRM? cT|2 cT|3 cT|4 f,:MRIS R25 m34 L-MRzs ma? Ht-Mnze WR l1 MRle MR 23 www cTaa T e153CTT`24 F I G 1NvENToRs .2 E P. e. WRIGHT J. RICE and R.c.oRFoRo ATTORNEYApril 15, 1958 E. P. G. WRIGHT ETAL 2,831,150

ELECTRICAL INFORMATION STORAGE cIRcUITs Filed Sept. 24, 1951 4Sheets-Sheet 3 I Attorney Aprl 15, 1958 E. P. G. WRIGHT ETAL 2,831,150

ELECTRICAL INFORMATION STORAGE CIRCUITS y Filed sept. 24. 1951 4sheets-sheet 4 From Tube CT (AH-3) From Tube C7'(/V+2) s InventorKGA/MIGHT- :Attorney United States Patent O web ELECTRICAL INF GRMATONSTORAGE CIRCUlTS Esrnond Philip Goodwin Wright, Joseph Rice, and RoyChalice Orford, London, England, assiwors to International StandardElectric Corporation, New York, N. Y.

Application September 24, 1951, Serial No. 248,082

Claims priority, application Great Britain September 29, 1950 19 Claims.(CI. S15-84.5)

This invention relates to electrical information storage circuits.

lt is well-known in the telecommunication art to store information bymeans of relays, multi-position switches, discharge tube counting chainsand like equivalents. By the operated or unoperated condition of relaysor tubes and by the position occupied by the wipers of multipositionswitches received information is retained. lt is common to scan thecondition of the storage devices in turn so that the information may beextracted. For instance a stepping switch may have each of its fixedcontacts connectable over a storage relay front contact to battery. Whenthe switch wiper steps on to a contact associated with an operatedrelay, battery can be applied to an outlet over the wiper arm.

information may be stored in numerical or non-uumerical code form andstorage or binary notation is becoming increasingly popular for example,in electronic computers.

@ne major line of development in this art is to store binary numbers inchains of interconnected gas discharge tubes in the form of patterns ofoperated and unoperated tubes. In one recently described arrangement, apattern is continuously circulated in one direction around a ring of gasdischarge tubes, an output being taken from one of the tubes whenrequired.

in another recent arrangement, a storage circuit consists of a number ofinterconnected magnetic cores which can easily be switched from one tothe other of two stebie saturated fiux conditions. With the lattercircuit aso, a binary pattern may be stored and moved in one directionalong the circuit, one tiux condition representing the binary digit land the other the digit O. A pulse pattern designating a binary numbercan be fed into one end of this magnetic storage circuit by means ofstepping pulses applied to the cores and when required an identicalpulse pattern can be extracted from the other end by a similarapplication of stepping pulses. A single-direction pattern circulationstorage arrangement has also been described in which the pattern may bemodified as it passes a particular point in the circulation, forinstance, a stored number may be multiplied or divided and the productor quotient thereafter circulated.

it will be seen that it has so far been possible to move informationalong such counting chains in a single direction.

According to the present invention there is provided an electricalinformation storage circuit comprising a number of interconnected staticelectrical switches on which informations is stored in the form ofoperated and unoperated switches and means for progressing the patternof operated and unoperated switches as a whole in each direction alongthe interconnected switches, and means for determining the direction inwhich movement is to take place.

The present invention also provides an electrical information storagecircuit comprising a number of static electrical switchesinter-connected into c. closed ring on ice which information is storedin the form of operated and unoperated switches and means forprogressing the pattern of operated and unoperated switches as a wholein each direction aro-und the ring and means for determining thedirection in which movement is to take place.

A feature of the invention is an electric information storage circuitcomprising a chain of interconnected gastilled multi-gap glow dischargetubes each capable of storing an item of information in the form of asingle anode/cathode gap being tired, means for firing any selected oneof the gaps in at least one of the tubes and means for replacing aselected discharge in one tube by a discharge across the correspondinggap in either of the next adjacent tubes. v

A further feature of the invention is an electric information storagecircuit comprising a chain of interconnected gas-tilled glow dischargetubes each capable of storing an item of information by its tired oruntired condition, means for firing any selection of the tubes, meansfor transferring the discharging condition of a tube to each of the nextadjacent tubes, and means for determining in which direction thetransfer is to take place.

Another feature of the invention is an electric information storagecircuit comprising a chain of interconnected magnetic trigger deviceseach capable of storing an item of information by its magnetic fieldcondition being in one of two stable conditions, the initial fieldconditions of all the devices being the same, means for triggering anyselection of such devices into a predetermined one of the said twoconditions and means for transferring the said predetermined fieldcondition of a trigger device to another trigger device either on oneside or the other thereof.

Use is made of static electrical switches.

The term static electrical switch as used in this specification is meantto embrace devices such as thermistor trigger circuits, hot or coldcathode gas-filled discharge tubes, hard tube trigger circuits,transistors and magnetic trigger devices.

It is thought that the following is a generic definition of the term,but in any case this attempt at definition must not be interpreted toexclude `any of the above specific examples.

A static electrical switch is a device having a permanently positionedelectrical path the effective impedance of which may be made to assumetwo widely different values, the selection of the one or the other valuebeing determined by the electric or magnetic field condition of acontrol element with two stable held conditions.

The invention will now be described with particular reference to threeembodiments thereof shown in the accompanying drawings in which:

Fig. l shows an important element of a gas-filled discharge tube circuitin which a decimal number may be stored and progressed in either of twodirections.

Fig. 2 is a schematic circuit diagram showing the complete decimalnumber storing circuit incorporating the invention, which circuitemploys a number of the circuit elements shown in Fig. 1.

Fig. 3 is a diagram of part of a gas-filled discharge tube circuit bymeans of which a binary number may be stored and moved in one directionalong a gas-filled discharge tube chain; this circuit is shown as anintroducs binary number may be progressed in either direction along 'thetube chain.

Figs. 6 and 7 are used to describe the operation of magnetic triggerdevices which are employed in the 'binary digit storage circuit ci Fig.8. Fig. 6 shows the desired form of hysteresis loop for the magneticcores employed and Fig. 7 shows a magnetic element for storage of asingle binary digit.

Fig. 8 shows a two digit section of a binary digit storage circuit inwhich the digits may be progressed in either direction along the storagecircuit.

The three embodiments of the invention are all concerned with theelectrical storage of information on ra number of interconnected staticelectrical switches. In the iirst embodiment, Figs. l and 2*, gas-lledmulti-gap cold cathode glow discharge tubes, are mainly employedalthough three electrode gas-filled discharge tubes are also used in anancillary manner. The information is registered in decimal notation onthermulti-gap tubes each which can be regarded as a group ofinterconnected static electrical switches within a single envelope.perated (i. e. discharging) and unoperated (i. e. unfired) gaps recordthe information by their condition. Stepping pulses are applied to thestorage arrangement and result in the decimal number being progressed,one unit storage space at a time. By applying a potential to one orother of two terminals the number can be progressed in either directionat will along the interconnected multi-gap tubes, which provide acirculating storage arrangement with a reversal feature. Also a decimalnumber can be multiplied or divided by ten and multiples thereof bymovement of the stored number the Aappropriate number of digit spaces tothe left or right respectively,

In the secondembodiment, the form of static electrical switch employedis the three-electrode gas-filled cold cathode glow discharge tube. Anumber of these together with associated components, such as resistorsand capacitors, are connected together to form. a tube chain on whichbinary-coded information may be stored, 'again by the operated andunoperated (i. e. tired and unred) condition of the tubes. Such.information may conveniently be received in binary notation, marks beingregistered as -operated tubes and' spaces as unoperated tubes, or viceversa, so that the pattern of operatedandunop* perated tubes representsthe stored information. The pat'- tern maybe progressedV in eitherdirection at will along the tube chain and the chain may be formed' intoa' ring so that stored information can be' continuously circulated.

Magnetic trigger devices. with two stable magnetic field conditionsv arethe static electrical switches. used for the third' embodiment. Theoperation is comparable with theV operation ofthe second embodiment,.information being stored by the magneticV field conditions' on a binarybasis. erated and the other as the unoperated condition. both the secondand third embodiments, asin the first,

thechoice of direction of'rnove'rnent is dependent upon which of twoterminals a@ potentialisz applied.

Turning now to Fig.'l 1,. the operation of' the: circuit which forms thefundamental basisfof the'irst embodiment of the invention, Fig. 2, willbe described.

The circuit of Fig. l consists essentially of a flip-hop tube pairCTland C'l'avgatingtube CT3 and avmultigap sequence discharge-tube MCTI.All these tubes are of' the gas-filled cold cathode glouI dischargevariety. When-the standingpotentials are initiallyY applied to thetubes,4 arrangements are made for CTI to beliredand for.the'anode/cathode gap numbered Gv of the multigap tubeto' be indischarge. Suchlresultscancbeobtained by'temporarily lowering the'cathodepotential in Veach 'case so that the main gap potentialdifference becomes greater than the" breakdown Value.Y Thediseharge',lonce Astarted, is maintained by the standing potentiaL In'operation;the: circuit'is: required tocounttne nega- One of the iiel'dconditionsis'known astheop- Iny til)

4 ave-going pulses reeervea at me point i aan fea t@ 'the cathode oftube GT3. The counting is performed by the discharge in the multi-gapYtube stepping oii for each pulse received, from the 0 to the l maingap, from l to 2 and so on in a manne; as has previously been described.ln order to achieve 'this operation, the circuit has first to betransformed from an inactive to adoperative state. Pulses applied at Pwhen CTi is' conducting will have no effect on the multi-gap tube MCTI.A positive-going start pulse is therefore appii'e'd at point S, thiscauses a breakdown between the trigger electrode and cathode of CTZwhich discharge spreads to the tube main gap and the tube conducts.l Theanode potential of CTZ falls and a negative-going impulse is transmittedby the coupling condenser CCi, to the anode of CT which is therebyextinguished. The start piiliiehas therefore resulted in CTZ being firedand CTI being extinguished. With CTZ conducting the positive potentialdeveloped across its cathode resistance Rl is applied to the triggerelectrode of tube CT3. It a negative pulse is now received at thecathode'of GT3 from the point P, a breakdown potential difference isdeveloped across thc trigger electrode/cathode gap and the tube istired. The stand ing potentials on this tube are arranged so that tiringand extinction takes place with every pulse received from point P, whichlatter pulses can `be supplied from a standard pulse generator.Negativelgoing pulses are developed across the anode resistance of GT3and these are applied via a condenser CCE and rectiiier MRt) circuit tothe common transfer electrode lead of the multi-gap tube MCTi. Thecondenser-'rechner' circuit is a pulse-shaping network; TheseA pulseswhich are' synchronised with thc pulses which are received at P, causethe discharge in tube lviCTlr to step in' time with the pulses'receivedat P. A cycle of operation is completed 4for every ten pulses applied tothe transfer electrode lead and the' completion of each cycle may besignalled by an output taken from 4tbc cathode of the 0 gap. Au outputmay alsobe taken if required, frorn any other cathode. The countinglprocess may be stopped at any time by the cessation of supply of pulsesto the point P or by theA firing of thestop' tube CTL the subsequentextinction of CTZ in the latter'ca'se removing the trigger electrodebias from CTS' thus' preventing it from firing and forwarding pulses to'M'CTl.

Although it has been mentioned above that the anodc/ cathode main gap Ohas been' initial'ly'iired, any particular gap may be tired at will bcensuring@ that the anode! cathode potential difference is larger in thatcase than in any of the others. y

in Fig. 2 there is shown a circuit in which circuit elcmentsidentical toFig. l have been utiliae'd, 'There are shown in Fig; 2 four multi-gaptubes MCTl, MCTZ), MCTi and MCT, each having: a gated input circuitsirnilar to theicircuit shown in Fig.4 l. Tube MCT3 has an inputcircuitu which consists* of Hip-flop tube pair CT?, CTS, and'gatingtubeCT?. Correspondingly, tube MCTf, has'its ip-floppair'CTiZ, CTT."` andgating tube CTM; tu-bev lviCTS has-its tliptiop' pair CT17, CTiS andgating tube' CT19; and' tube' MCTtiy hasVv itsfiip-op pair CTM, CTZS'and gating tubeV CTZ. In' this ligure, the tube MCT3 is the input tube;its associated tubes CTS and CT9 receiving tliestart pulses S andnegative pulsesP, respectively. In this'` showing thev tube MCTS' isadapted to4 count units digits and the tube MCTS tens digits.

The Fig. 2 circuit comprises a two-digit decimalstorage with thefacility for movement of these digits inl either direction relative tolan' imaginary decimal point; In the detailed description" to-I follow'it will be shown" how the stored digits canbe moved a=step at atinietothe right and-how the` least-significantdigit can be madetorappear ata receivingpointl Consider that tens and units`digits'areistorcdfby par-' ticular gaps being fired in. MCT3 and MCTSrespectively and that CTI, CT 7, CT12, CT17fand- CT20 are fired, theremainder of therthree-electrode tubes Vbeing extinguished Cil Underthese conditions, when pulse S is received, the

tube CTZ@ which has previously been fired is extinguished. This is dueto the tiring of tube CT21 `by the start pulse. With the tube CT21fired, a positive potential is developed across its cathode resistancewhich potential blocks the rectiers MRi3, MRM and MRS. The start pulse Salso causes tubes CT2, CTS, CTiS, CTTS and CT23 to strike in each caseopening the respective multicathode tube gates. Negative-going pulsesare now applied at all the points P of the circuit causing each of themulti-cathode tubes to step. When MOTS arrives at its position,rectifiers MRTo and MR17 are `both biased positively. With MRT?, and MRWboth blocked, a positive potential is applied over rectifiers MRlS andMRZZ respectively to the trigger electrodes of tubes CT1 and CT?. Thesestop tubes, therefore, are both tired extinguishing GT2 and CTS,respectively. With CTZ and CT extinguished, the tube gates CTS and CT9are closed. Further pulses at the points P will not cause MCT and MCT3to take any further steps. MCT3 is stepping from its initial position tot), MCTl takes a number of steps equal to the complement to 10 of theinitial position of MCT3, i. e. the complement of the units digit. In asimilar manner, when MCTS reaches cathode 0 the 4bias developed acrossthat cathode is applied to block the rectiers MR32 and MR33. With MRMalso blocked, a positive potential is applied over rectiliers MR26 andMR31, respectively, to the trigger electrodes of tubes CT12 and CT17causing these tubes to tire, so extinguishing tubes CT i3 and CT18respectively. Tube gates CT14 and CT19 are thereby closed andmulti-cathode tubes MCT4 and MCTS take no further steps. MCT4 will beleft recording the complement of the tens digit initially found on tubeMCTS. Tube MCT6 during this time makes a complete cycle. When it reachesthe O cathode it applies a potential to block rectifier l/IR39 and, withMRlS blocked, a positive potential is applied over rectifier MRSS to thetrigger electrode of tube CT22 which res, extinguishing CT23, closingthe tube gate CT24 and stopping the multi-cathode tube MCT. A furtherstart pulse S is now applied to all the points S of the circuit whichretires tube CTM) extinguishing CTZT and also retires the start tubes,such as CTZ, of all the multi-cathode tubes. Now pulses at point P stepthe multi-cathode tubes as before. steps its discharging condition tothe0 cathode once more. When this is reached a positive potential isapplied to block both rectiers MRZd and MRZS. Rectier MRT@ is blocked bya positive potential developed across the cathode of tube CT20,rectifier MRS is blocked 'by the positive potential applied to point F,and, therefore, a positive potential is applied over rectifiers MR19 andMRS() to tubes CTT and CT17 respectively. These are the stop tubes ofmulti-cathode tubes MCTT and MCTS respectively, so that the latter tubestake no further steps. Tube MCTS will be remembered to have started thisparticular movement when it was at the 0 position and it is thereforenow at the position denoting the complement of the position of MCTl, orin other words, it is now recording the original units digit. Thecomplement of what was first in MCTS has been temporarily stored in MCTIand the complement of the complement, that is the original number, hasnow been transferred to MCTS.

MCT4 at the -beginning of this movement is recording the complement ofthe tens digit originally stored in MCTS, but when it steps and reaches0, MR34 and MR35 are both blocked by a positive potential developedacross the resistance in its 0 cathode circuit. MRll and MR2 are blockedalso so that a positive potential is applied over rectifiers MR2? andMR36, respectively to tubesY During the time that f- Tube MCTl f CT12and CT22. The firing of these tubes effects the stopping of any furtherstepping in tubes MCT4 and MCT6. In the same way as MCTS is nowrecording the original units digit, MCT6 is now recording the originaltens digit. Tube MCT3 makes a complete cycle and stops itself at the 0cathode, because with MRM and MRlZ blocked the positive potential is fedover rectier MR23 to the stop tube CT7.

It will be clear that the digits have moved along one space, the unitsdigit is now stored in the tube which originally stored the tens digit,and the tens digit is to be found in tube MCT6. This action could berepeated, the original tens digit being passed to other tubes not shown.It will now be described how the original units digit will in turn bepassed to the multi-cathode tube MCT6.

A further S pulse causes CT21 to strike once more, extinguishing CTZ()and all the start tubes are re-iired. Once more the multi-cathode tubesstep their discharging condition under control of the negative pulsesapplied to their respective gating tubes. As before, multi-cathode tubeMCT3 performs a complete cycle and stops. At the same time the tube MCTSsteps its discharging position until it reaches the 0 cathode positionWhere it produces a blocking potential for rectifier MR32, MRM isblocked because CT21 is now operated and therefore, a positive potentialis applied over rectifiers MR26 and MRSl respeetively, to tubes CTTZ andCT17, which tire. These stop any further movement of the dischargingposition in tubes MCT4 and MCTS. MCT4 is therefore, now recording thecomplement to ten of the original units digit which has been received bytransfer from MCT5. During the time that MCT4 and MCTS have beenstepping, MCT steps from the tens digit position to Here a blockingpotential is developed for rectifier MR39 and because MR15 is blocked byCT21 being red, a positive potential is applied over rectifier MR38 totube CTLZZ which stops any further movement of the discharging positionin tube MCT6. Tn a similar manner to that already described for thetransfer of the tens digits to the tube MTC6, the next S pulse causesthe complement of the number in MCT4 to be transferred to MCT6. Thus,the units digit is referred to tube MCTe. It will be seen that as theunits and tens digits clear from the multicathode tubes, these tubesmake complete cycles stopping each time at the 0 position.

In the operation described above, the tens digit has been transferredfirst to the tube MCT6. By applying a blocking potential to the point Rinstead of to the point F, the reverse operation can -be made to takeplace. It should be clear that Whichever of the points F and R does nothave a blocking potential applied thereto, an earth is applied to it.`#1i/ith R at a positive potential and F at earth, instead of the numberin MCTS being transferred to MCT6 via MCT4, it is transferred via MCT,MCT3 and MCTi. Also the number in MCT3, that is the units digit, whichformerly pass to MCT6 via MCT, MCTES, and MCT4, in that order, nowtransfers Via MCT?. only.

The description `above shows how a decimal number having two digits canbe caused to progress along a storage circuit in either direction. Ithas been indicated that this circuit could be extended so that decimalnumbers having a number of digits could be made to do the same thing.The tube MCT6 may be considered as a reviewing point past which thedigits of the decimal number are taken in turn. Leads might be takenfrom the cathode MCT6 so that the number stored could be scanned, digitby digit, as it passes the tube MCT6.

Attention will now be turned to the storage of information in binarycode form. A known form of gas discharge tube counting chain shown inFig. 3 in which the pattern of discharging and non-discharging tubes canbe progressed in one direction along the chain will now be described. Itis also known that such a pattern may repi? resent a binary number orother information in binary code form.

`Consider that the pattern stored on the tubes futhe chain at someparticular time includes CTA beingffired and CTB being extinguished. Apositive-going driving pulse is lapplied to all the tubes ofthe chain incommon. This pulse extinguishes the discharge in CTA. The rising anodepotential charges the condenser C1 and at lthe same time applies a pulseto the next tube CTB through C2. This tube conseqliently lires when itsVnormal7`c`a`thode potential is r'e-applied on the trailing edge of thedriving pulse. The charge on condenser` C1 blocks rectifier M1141 in the'event of tube CTA re-'ring in conformation with the pattern moVe'rnentvand isolates th'e trigger electrode of CTB from any ill-eiects diie tofall in potential on the anode of CTA. If CTA triggers, Ci dischargesthrough R2 duringthe pulse interval until it is caught at the anodepotentialmofV CTA. A rectifier-resistance circuit MRZLRQ: is includedbetween the source of biasing potential B and the 4tiigf'ger electrode'of tube CTB. This gives a D. C. restoring provision for condenser CZ,preventing the trigger electrode potential falling below B. Thewaveforms 'ofthe driving pulses in relation to the anode potentials'ofCTA and the condenser C1 potentials are shown in Fig. 1. From the latterhgure it will be seen that when the first, secondV and third drivingpulses are received, the anode potential is raised. This indicates thatin each case CTA had previously been conducting. At the end of the thirddriving pulse however CTA anode potential remains at the positive H. T.potential. This is due to the fact that when the pattern beingconsidered is moved to the right three steps, CTA records an element ofinformation opposite in sign to those previously recorded. With theoperation of this Fig. 3 circuit in mind, attention should be Vturned tothe second embodiment or the invention to which Fig. 5 refers.

In the circuit of Fig. 5 information is again stored in binary code formbut this time the pattern of operated and non-operated tubes can bemoved in either direction. The initial storage of the information can beachieved either by temporarily lowering the potential of the cathodes ofthe appropriate tubes or by progressing ,the storage pattern into thechain from one end as has been previously described. The direction ofmovement is determined by the application of biassing potential B to oneof two leads LF and LR. 'This choice of application is showndiagrammatically in the figure by` a movable relay contact over whichthe bias potential B is fed to either of the leads LF or LR. Theindividual tubes of the gas tube chain are shown as tubes CTN, +1),CT(NI2). On these,1binary elements of the stored information arerecorded by their operated or unoperated condition. Componentscomparable with those indicated in Fig. 3 are given the same references.

Assume that the stored pattern at some particular moment includes CTNand CT(N-l-l) tubes both o perated, CT(N-1) (not shown) and CT (N-l-Z)being extinguished. Assume also that the bias batteryrB is connected tothe LF lead. As before, driving pulses are supplied over a lead commonto the cathod'es of all the tubes.

On receipt of the first of the driving pulses after the momentconsidered, both CTN and CT(N +1) tubes will be extinguished. CondenserC1 is Charged up and a pulse is passed forward over condenser C2'.Because of the bias B applied over R3 and M1142 the right-hand side ofthe condenser C2 has been standing alla Ypoten1 tial B. Hencewhen thepulse, is supplied thereto,apo-V tential considerably kgreater than B istopbehoundat the C2 side of rectifier NIR/44. This rectifier has only apotential B (applied over resistance R5) on its other side and ittherefore conducts in the ,fo4V 'reetiom The trigger electrodevo'fptub'e CTQV +1) hasha triggering potential applied to it so that itreltire's upon the end of 8 the first driving pulset In thisway thecondition which been 'ferdd by the CTN t'llbe vhas been passed frwjrd'fqfheCTtN-tjl) tube.. y i

The pu'l 'developed by the eXl of tub/e CTN and 1the consequent chargingand discharging 'of condenser C1 is passed forward via condenser C2 toei'iect the vre-firing of tube'CT(N-{l) but the pulse passed forward'over c'or'ldeiiser'C3 does ntietect the ring of tube CTUfJ-l). Thereasonl for thism'will now be 'eitplained. because the battery B isconnected tothe lead LF, 'meteen vLR is 'at earth potential. Hence theplate of condenser C3- onpthe side away from the anode connections oftube CTN stands at earth potential. 'A pulse passed by the condenser lC3'is presented to a rectifier corresponding to rectifier yMRiS, at theCT(N-l) tube', but at a low level, A's this rectifier has a potential Bstanding ou its farther side it will not conduct so that inconsequenceitu'be CTfN-l) will not beffired.

initially, tubes CTN and 7C'l`(N-il) were fired so that thereceipt ofone driving pulse will resu'lt in tubes CT(N+1) and CTUV-l-jZ) beingiired instead. lf the potential condition of the bias leads VLF and Li?.had been reversed, it is clear that the movement of the pattern wouldhave been in the opposite direction, one driving pulse then resulting intubes CT(N-l) and CTN being fired. e e Y In this manner, a pattern maybe moved 'in either direction along 'a tube chain at high speed by theapplicationV of driving pulses to the'tube cathodes, coupled with apositive bias potential being applied to one of two 'conlmon leads', the'other being at earth potential. One of the tubes may beconsidered'a's areviewing tube, the p'att'ern being scanned as it passes that point. Thestored information may be extracted by a lead taken from the cathode ofthe reviewing tube via suitable decoupling means'.

In the third embodiment Vof the invention use has been made of amagnetic form of static electrical switch iustead of the gas-filled glowdischarge tube form "ernployed in the earlier embodiments. 'Toappreciate the operation of this `magnetic "static -electricalswifchFigs. 6 and 7 have been included. The switch requires a vcore having asubstantially square loop hysteresis characterstic as shown in the curvein Fig. 6. This material when saturated in Veither direction retains itsrelnanen't niagnetism at a flux density practically the same 'as thesaturation u'x for an extremely long duration, e

Consider now a closed magnetic core of thin section (to reducehysteresis losses) on which are Wound three coils.V The left-handportion lof Fig. 7 may be referred to. There the 'cofre has been shownin a 'rectangular formation but that convention is simply for ease ofdrawing. Imagine first a magnet'ising pulse being fed via the inlet IP(Fig. 7), this pulse being of such polarity and amphtude that the coreis positively saturated. On the removal of the pulse, theV corecondition will return to the 'point K1 (Fig. 6). If now a furtherYsimilar pulse is fed to the inlet DPl (Fig. 7), the core flux will makean excursion from K1 to K2 and back again (Eig. 6). in the idealsituation therewill be no Vflux change in the cere and in 'practice thelinkage with a third coil on the core will be negligible. I'f however,the initial pulse applied to the IP inlet is of the opposite polarity,then the receipt of the DPI inlet pulse will cause the core fluxcondition to make an excursion from K3 to K2 returning to its remanentposition at Kl. Hence there has been a large change of iluX from oneVstable condition to another and the 'linkage with a 'third coil will beconsiderable. Hence the polarity of the pulse initially applied can bedetected by the presence or absence of 'an output pulse from the 'thirdcoil providing the polarity of the pulse applied to the DPl inlet isknown.

It will be appreciated .that this device may be used as thebasic elementof a pattern movement chain. If the polarity of the pulse initiallyapplied to the core is such that, with a predetermined polarity of pulseapplied to the core by the DPl inlet, an output pulse is obtained, wemay conveneintly say that the information stored in the core by itsinitial remanent condition is the binary digit l. An initial pulse ofthe opposite polarity will then be the binary digit 0. it now the outputpulse from that core is fed to a coil mounted ou a second core so thatthere is induced in the latter a renianent flux condition of polarityindicating the storage of the binary digit l, the digit originallystored in the first core may be said to be passed to the second core.This arrange ment is shown in Fig. 7, the output coil OC of the firstcore being connected to the input coil of the second. Whatever fluxcondition the first core was in after the initial pulse had beenreceived from inlet iP, the application of a pulse to inlet DPI leavesthe core always in the same remanent condition. This is such that for abinary digit O, the core condition remains the same. If now a pulse ofpolarity representing the binary digit l is received via IP, a change oflinx occurs once more and the coil OC is linked. The direction of changehowever is in the opposite direction from that previously described, itis from K1 to K4 and back to K3 (Fig. 6). The direction of the currentinduced in the coil OC is in the opposite direction also and because ofthe rectifier MR46 no output pulse is passed forward. Hence it is onlyin response to the receipt of an appropriate driving pulse at the inletDPl that a binary digit l can be forwarded.

With the binary digit l forwarded to and stored on the second core, adriving pulse is in turn applied to the inlet D132. A considerable fluxchange takes place and an output pulse is received at the terminals OP.No backward current aliects the tirst core because the only coilconnected thereto is short circuited for these induced currents by therectifier MRM.

A number of cores, pairs of which are connected as shown in Fig. 7, maybe connected together. With pulses representative of information inbinary code form fed into the inlet of the first core and driving pulsesapplied in turn to two leads commoned to alternate core driving inlets apattern of core liux conditions, representing a binary number, may bepassed along the interconnected cores. Such an arrangement has alreadybeen described. Alternatively the information could be initially storedby having an additional coil on alternate cores by means of which thosecores are preset into appropriate conditions representative of theinformation.

In the third embodiment of the invention shown in Fig. 8, magnetictrigger devices of the kind described above and shown in Fig. 7 are thestatic electrical switches employed. A pair of cores is provided foreach stage of a pattern movement chain. The nth and the (iz-|-l)thstages are shown in Fig. 8. Once again the movement is arranged to be ineither direction along the chain according to which of two leads LF andLR has applied thereto a blocking potential. rl`he two trains of drivingpulses required are applied to the cores via the channels DPlC and DPZC.The driving pulse trains are of the same frequency but 180" out of phasefor steady progression of the pattern.

Consider first the nth stage. Any pulse passed forward from the (it-Dthstage is received by the appropriate coil and the informationrepresented thereby is re-stored in the core. A driving pulse receivedover the DPiC channel causes an output pulse to be developed across theoutput coil OC when a binary digit l has been stored in the coil. Asbefore this pulse is fed over rectifier MRGS to the inlet coil of thesecond core of the same stage. in this case, however, the informationcan only be passed forward if a blocking potential has been placed onthe LF lead. This is because the blocking potential prevents currentpassing to earth over R6, MR49 and R7. Resistance R6 is large comparedwith the forward resistance of MR@ and with R7 so that when this path l@is free, i. e. there is no blocking potential on LF lead, the greatestpotential drop is in R6. Hence no appreciable pulse can be passedforward over MR48. This rectilier gating circuit is known. The rectifierMRS@ corresponds to MR47 in Fig. 7.

It will be apparent from the drawing that the connections for theforward movement of the pattern shown in Fig. 7 are duplicated in Fig. 8to permit of the reverse movement also. A blocking potential on lead LFbut not on LR permits forward movement of the pattern only. With theconditions of these two leads reversed retrogression of the binarypattern is obtained.

Consider the binary pattern 1010 stored on the magnetic trigger stages(ri-2) to (n+1) respectively i. e. in both of the (n-2)th and nth stagesthe left hand first core will be at the binary digit l representativelinx condition, all the remainder of the cores'in each stage being inthe flux state correspon-ding to the binary digit 0. The lead LF has theblocking potential applied thereto.

When the first driving pulse is received over the DPiC channel thebinary digit l on the left hand core of the nth stage is transferred tothe right hand core leaving the left hand core in the 0 representingcondition. Similar transfer from left to right core takes place in the(fz-2Mb stage. ln the other stages the first driving pulse produces noresult.

A driving pulse is next received over the DPZC channel. This has noeffect except on the right hand cores of the (n-Z)th and nth stageswhere it produces the transference of the binary digits l stored thereinto the left hand cores of the (fz-Uth and (n-i-l)th stages respectively.Hence the application of two driving pulses in turn over the twochannels has resulted in the pattern itil@ being progressed to storageon the (iwi-Util to (.'z-}-2)th stages.

- Consider now the simple case of a binary digit l being stored by theremanent flux condition of the (n-l-Uth stage left hand core, whichdigit it is desired to transfer to the nth stage. The blocking potentialcondition is applied to the LR lead, the LF lead being left earthedthrough R7. A driving pulse applied over DEiC channel causes each of theother coils mounted on the core being considered to experience aconsiderable flux linkage. An output pulse can only be forwarded by oneof these four coils however for reasons now to be explained. Therectiiiers MRSl and MESZ are arranged to provide short circuit paths forcurrents induced in thc coils across which they are connected. Hencethese coils transmit no pulses. The coil OCR produces a puise but thisis dissipated by the dropping resistance it@ in the circuit through R3,rectier MRSS in the forward direction, resistance R7 to ground. Hence nopulse is forwarded to the right hand core of thc (z-l-Dth stage.Distinct from these three coils the coil OCL does produce an outputpulse, which is forwarded over rectifier MRM to the right hand core onthe nth stage. ri`his is because with rectifier MRS blocked therechner-resistance gate MRSS-R@ is open. Hence the digit l istransferred by a DPlC pulse from its original storage to the right handcore of the nth stage. Rectiiier is blocked so that the RliP--MRESS gateis open. Rectiiers Mltl and Mi57 provide short circuit paths acrosstheir respective coils. Resistance Ril provides a dissipating resistancein the circuit through rectifier MRSS and resistance R7 to ground. inthese circumstances the next stepping pulse received over the DPECchannel edects the transference of the binary digit l to the left handcore of the nth stage. in this way the retrogression of a pattern isobtained.

In this embodiment as in those previously described one stage may beconsidered as the reviewing stage and the pattern scanned as it is movedpast that point.

In any of these embodiments the static electrical switches, or groupsthereof, may be arranged in a ring so that continuous circulation ofstored information is obi. i tainable. A controlled number of driving pulsesmaybe applied to the storage circitso tha't the information can bemoved a predetermined number of steps. with one stage being consideredas ar'eviewing point the pat# tern may be modified as it moves past thatpoint.

This Vinvention Aenables numerical information to be multiplied ordivided by the radix on which the storage is based or multiples thereof,by moving the pattern' the appropriate number of places to the left orright respectively. Y Y j While the principlesk of the invention havebeen de# scribed above in connection with specific embodiments, andparticularV modifications thereof, it is to be clearly understood thatthis description is made only by way of example and not as a limitationon the scope of the invention. j

What we claim is: y A

Vl. An electrical information storage circuit wherein the pattern ofstored information will be progressed as 'a whole along a chain ofinterconnected storage devices comprising a plurality of two-conditionstatic electrical switches, alternate of said switches constitutingstorage elements adapted by a first condition of operation to storeinformation in a given radix, intervening of said switches intermediatesaid storage elements constituting repeating elements, each of saidrepeating elements adapted to assume a first condition of operationcomplementary to the first condition of operation of an adjacent storageelement, means for altering the condition of operation of given of saidstorage elements in response to the application of additionalinformation thereto, separate coupling means in'- ter-coupling adjacentof said static switches, first transfer means for transferring thealtered condition of a storage element to an adjacent repeating element,additional transfer means for transferring the altered condition of arepeating element to the next adjacent storage element anddirection-determining means coupled to each of said coupling means forcontrolling the direction in which said transfers shall occur uponoperation of respective of said transfer means.

2. An electrical information storage circuit as claimed in claim 1,wherein said switches are interconnected to form a closed ring.

3. A circuit as claimed in claim 1 in which one of the saidinterconnected static electrical switches is arranged to be a reveiwingpoint, and which comprises means for scanning the stored information asit is progressed in either direction past the said point.

4. A circuit as claimed in claim 3 in which means are provided formodifying the stored information as it is progressed past the saidreviewing point.

5.` A circuit as claimed in claim 3 further comprising means fortransmitting the said stored information as an impulse train `)vhereinthe spacing between impulses varies and is dependent upon the saidpattern of operated and unoperated switches.

6. A circuit as claimed in claim 3 in which the switches are arranged tostore information on the basis of radix two, whereby information inbinary notation may be stored.

7. A circuit as claimed in ciaim 3 in which the switches are arranged tostore information on the basis of radix ten, whereby numericalinformation in decimal notation may be stored.

8. A circuit as claimed in claim 3 wherein said electrical switches aregas-filled glow discharge trigger circuits.V Y

v9. A circuit as claimed in claim 3 wherein said static electricalswitches are magnetic trigger circuits.

10. A circuit as claimed in claim 3 in which the pattern progression isobtained in either direction in step by st ep movement under control ofthe application of driving pulses to the circuit applied by respectiveof said transfer means.

static tube ll.v electrical information lstorage circuitas claimed inclaim 2, wherein each` 'of said repeating elements" corriprise's a pairof terminals and said directioii-deterniining means comprises a sourceof potential and a switch, said switch adapted to selectively apply saidpotential to corrsponding terminals of said pairs, the direction ofprogression along said switches being determined by the ap'- plicationof said potential to different corresponding terminals of said pairs, apotentialdifference one direction between corresponding first terrr1i1ia lsof said pairs permitting progression in one direction only 'anda potential difference in the other direction between cofrespondingsecond terminalsof said pairs permitting progression in the otherdirection only.

12. An electric information storage circuit as claimed in claim i,wherein said static electric switches comprise a chain of interconnectedgas-illed multi-gap glow discharge tubes each capable of storing an itemof informa-4 tion in the form of a single anode/ cathode gap beingtired, under control of said altering means, said repeating elementsadapted to repeat in a corresponding gapin a tube a discharge of aselected gap in either 'of the next adjacent tubes.

i3. A circuit as claimed in claim 12 in which the replacing meanscomprises a further chain of interconnected gas-filled muiti-gap glowdischarge tubes an intermediate step in vthe said replacement being theeffecting of a discharge across a gap in a tube of the said furtherchain which is complementary to the said selected discharge in the saidonel tube.

14. A circuit as claimed in claim ll, wherein said switches comprise achain of interconnected gas-filled glow discharge tubes and wherein saidrepeating elements further comprises a plurality of pairs of gatingnetworks, cach connected to one of said terminais one pair associatedwith each of the tubes of said chain, the rst network each pair coupiedbetween given tubes Aof said chain and the tube adjacent thereto on oneside thereof and other network of each pair coupled between said vgiventubes and the tube adjacent thereto on the opposite' side thereof,corresponding networks adapted to be gated 'operi in response to theapplication of said Apotential to its associated terminal.

15. A circuit as claimed in ciaim lli, wherein said altering meanscomprises a source of pulses, said source coupled to each tube in saidchain and adapted to have 'its output applied simultaneously to cach vofsaid tubes.

16. A circuit as claimedin claim 14 in which 'a 'election of tubes islfired and in which the transference -Ieach of the discharging conditionsto the next adjacent tube, inthe same direction, occurs simultaneously.

17. An electric information storage circuit as ciaimed in claim 1,wherein said switches comprise 'a chain of interconnected magnetictrigger devices each capable cf storing an item of information by itsmagnetic field condition being in one of two stable conditions, theinitial field conditions of ali the 'devices being the same, saidaltering means adapted to trigger any selection of such devices into apredetermined one of the said two conditions said cpeating elementsadapted to repeat said predetermined field condition of a trigger'device to another Vtrigger device either on one side or the otherthereof.

18. A circuit as claimed in claim 17 wherein said repeating elementscomprise 'two Vsets of gating networks between adjacent trigger devicesand wherein said dimotion-determining selectionmeans controls thedirection of ltransferfof the predetermined field condition, said lastnamed 'means adapted for opening either all the gates of one setpermitting the Ysaid transfer to take place inbne direction or all thegates of the other set permitting the said transfer to take place in theopposite direction.

19. A circuit as claimed in claim 18 in which all the gates of either'set are opened simultaneously.

(References on following page) References Cited in the le of this patentUNITED STATES PATENTS Bascom Nov. 15, 1949 Thompson Aug. 22, 1950 HoughApr. 3, 1951 Hough May 22, 1951 Hagan Nov. 20, 1951 Hagan Nov. 20, 1951Holden Jan. 22, 1952 Phelps Feb. 5, 1952 Dimond Oct. 14, 1952 Odell Aug.18, 1953 Edwards Jan. 19, 1954 An Wang May 17, 1955 Jacobs Oct. 4, 195514 OTHER REFERENCES Publication, Princeton, N. J. Institute for AdvancedStudy, 2nd Interim Prog. Report on the Physical Realization of anElectronic Computing Instrument, July 1947,

5 pp. 30, 31, 31A, 32, 32A, 33, 34, 34A, 34B, 34C, 35,

Publication I, Journal of Applied Physics, January 1950, pp. 49-54.

Publication II, Magnetic Cores, Thesis by Munroe K.

10 Haynes, pp. 33 to 35, 46 to 50, 57 and 58, Dec. 28, 1950.

Publication III, Electronics, January 1951, pp. 108

